A liquid crystal display panel mainly includes a color filter substrate, an array substrate disposed oppositely and a liquid crystal layer between the color filter substrate and the array substrate; and displays images with illumination by the backlight source or natural light. For different types of light source, liquid crystal display panels are mainly classified into transmissive, reflective and transflective ones.
A transmissive liquid crystal display panel mainly uses a backlight source as the light source, that is, a backlight source is provided behind the liquid crystal display panel, transparent electrodes are used for pixel electrodes on its array substrate and function as transmissive areas, which is advantageous for light of backlight source to transmit the liquid crystal layer to display images. A reflective liquid crystal display panel mainly uses a front light source or an external light source as its light source, and reflective electrodes of metals or other materials with good reflection characteristics are used on the array substrate as reflective areas, which is advantageous for reflecting light of front light source or external light source. A transflective liquid crystal display panel may be considered as a combination of a transmissive and a reflective liquid crystal display panel with both reflective areas and transmissive areas provided on the array substrate, which can use both the backlight source and the external light source for displaying.
Transmissive liquid crystal display panels have an advantage of capability to display bright images in dark circumstance and a disadvantage of small proportion of light that can transmit to the light emitted by the backlight source, i.e., a low utilization ratio of backlight source. Thus, in order to enhance display luminance, it is required to enhance luminance of backlight source drastically, which thereby causes high energy consumption. Reflective liquid crystal display panels have advantages of utilizing external light sources such as sunlight and relatively low power consumption, and disadvantages of incapability of displaying images in the dark due to the dependence on external light source. Transflective liquid crystal display panels have the advantages of both transmissive and reflective liquid crystal display panels and can be used both in dark circumstances such as in a room and in bright circumstance such as outdoor. Therefore, they are widely used as display units of products such as mobile products, e.g., cell phones, digital cameras, palm computers and GPRS.
Transflective liquid crystal display panels include single cell gap (uniform liquid crystal layer thickness for transmissive and reflective areas) and thick cell gap (non-uniform thickness of liquid crystal layer for transmissive and reflective areas) types.